A machine tool which performs machining, such as cutting, by moving a tool relative to a workpiece is known in a conventional technique. In such a machine tool, a numerical control-type machine tool is known which specifies a path of a tool by coordinates of a predetermined axis or the like and performs machining by automatically moving the tool with respect to a workpiece. The numerical control type machine tool can perform machining using a desired tool path at a desired feed rate by describing coordinates and a movement speed in a machining program.
Patent literature 1 discloses a speed control method for moving a tip end of a tool at a given command movement speed when machining is performed by changing an angle of the tool. This patent literature discloses that a distribution moving amount of each predetermined period is calculated on condition that linear interpolation is performed using only a linear moving axis without regard to an angle change of a tool, and a position deviation caused by a rotational movement later occurring on a tip end of the tool is added to the distribution moving amount.